import asyncio  # 标准库模块

async def say_after(delay, what):
    await asyncio.sleep(delay)  # 添加await关键字
    print(what)


def hello():
    return "编程小菜鸟"
async def main():
    await asyncio.gather(
        say_after(1, 'hello'),
        say_after(7, 'world'),
        say_after(2,hello())
    )

asyncio.run(main())

